My invention relates to a novel device for automatically preventing backup of sewage in drain lines, particularly in metropolitan residential areas, in the event the sewage disposal system reaches an overflow condition during a period of heavy rainfall.
Due to the burgeoning population growth, sewer systems built 20 to 30 years ago are becoming inadequate to dispose of the combined sewage and rainwater in periods of heavy rainfall. Overflow of the system occurs, resulting in backup of sewage in the drain lines of residences and buildings where none had occurred previously. Livable and storage areas below grade become flooded causing incalculable damage and anguish.
There are a number of devices on the market for preventing sewage backup. Two devices such as (1) an overhead drain line, or (2) a check valve located between the dwelling and the sewer are effective but very costly to install in established buildings. Other simple and inexpensive devices can be used such as check valves or standpipes in the floor drains but present an element of risk. Instances are known where water seepage occurred under the floor resulting in a pressure sufficient to break up the floor. All other known devices for preventing sewage backup are either variations or combinations of the above.
My invention overcomes the drawbacks of the above mentioned devices in that it is relatively inexpensive to manufacture and is easily installed. Since it is installed in the drain line at a remote distance from the building, it provides safety from water seepage under the floor. In addition, since reliability is of prime importance, means are incorporated in the device to simulate a backup condition for checking the integrity of the device.